vl53l1x: Check data ready and clear interrupt in read().

Author: nedseb

lib/vl53l1x/vl53l1x/device.py

@@ -136,40 +136,31 @@ def reset(self):
         machine.lightsleep(100)
         self._write_reg(0x0000, 0x01)
 
+    def start_ranging(self):
+        self._write_reg(0x0087, 0x40)
+
+    def stop_ranging(self):
+        self._write_reg(0x0087, 0x00)
+
+    def _is_data_ready(self):
+        polarity = self._read_reg(0x0030) & 0x10
+        ready_val = 1 if polarity == 0 else 0
+        return (self._read_reg(0x0031) & 0x01) == ready_val
+
+    def _clear_interrupt(self):
+        self._write_reg(0x0086, 0x01)
+
+    def _ensure_data(self):
+        if not self._is_data_ready():
+            self.start_ranging()
+            for _ in range(100):
+                if self._is_data_ready():
+                    return
+                machine.lightsleep(10)
+
     def read(self):
-        data = self.i2c.readfrom_mem(self.address, 0x0089, 17, addrsize=16)  # RESULT__RANGE_STATUS
-        # range_status = data[0]
-        # report_status = data[1]
-        # stream_count = data[2]
-        # dss_actual_effective_spads_sd0 = (data[3] << 8) + data[4]
-        # peak_signal_count_rate_mcps_sd0 = (data[5]<<8) + data[6]
-        # ambient_count_rate_mcps_sd0 = (data[7] << 8) + data[8]
-        # sigma_sd0 = (data[9]<<8) + data[10]
-        # phase_sd0 = (data[11]<<8) + data[12]
+        self._ensure_data()
+        data = self.i2c.readfrom_mem(self.address, 0x0089, 17, addrsize=16)
         final_crosstalk_corrected_range_mm_sd0 = (data[13] << 8) + data[14]
-        # peak_signal_count_rate_crosstalk_corrected_mcps_sd0 = (data[15] << 8) + data[16]
-        # status = None
-        # if range_status in (17, 2, 1, 3):
-        # status = "HardwareFail"
-        # elif range_status == 13:
-        # status = "MinRangeFail"
-        # elif range_status == 18:
-        # status = "SynchronizationInt"
-        # elif range_status == 5:
-        # status = "OutOfBoundsFail"
-        # elif range_status == 4:
-        # status = "SignalFail"
-        # elif range_status == 6:
-        # status = "SignalFail"
-        # elif range_status == 7:
-        # status = "WrapTargetFail"
-        # elif range_status == 12:
-        # status = "XtalkSignalFail"
-        # elif range_status == 8:
-        # status = "RangeValidMinRangeClipped"
-        # elif range_status == 9:
-        # if stream_count == 0:
-        # status = "RangeValidNoWrapCheckFail"
-        # else:
-        # status = "OK"
+        self._clear_interrupt()
         return final_crosstalk_corrected_range_mm_sd0

tests/scenarios/vl53l1x.yaml

@@ -15,6 +15,14 @@ mock_registers:
   0x0000: 0x01
   # MM_CONFIG__OUTER_OFFSET_MM (0x0022): used during init
   0x0022: [0x00, 0x00]
+  # GPIO__TIO_HV_STATUS (0x0031): data ready (bit 0 = 1 when polarity=0)
+  0x0031: 0x01
+  # SYSTEM__INTERRUPT_CLEAR (0x0086)
+  0x0086: 0x00
+  # SYSTEM__MODE_START (0x0087)
+  0x0087: 0x40
+  # GPIO__HV_MUX__CTRL (0x0030): interrupt polarity (bit 4 = 0 -> active low)
+  0x0030: 0x01
   # RESULT__RANGE_STATUS (0x0089): 17-byte result block
   # Bytes: range_status, report_status, stream_count,
   #         dss_spads(2), peak_rate(2), ambient_rate(2),
@@ -39,6 +47,35 @@ tests:
     expect: 250
     mode: [mock]
 
+  - name: "Data ready check works"
+    action: script
+    script: |
+      result = dev._is_data_ready()
+    expect_true: true
+    mode: [mock]
+
+  - name: "Read clears interrupt"
+    action: script
+    script: |
+      i2c.clear_write_log()
+      dev.read()
+      log = i2c.get_write_log()
+      cleared = any(reg == 0x0086 and data[0] == 0x01 for reg, data in log)
+      result = cleared
+    expect_true: true
+    mode: [mock]
+
+  - name: "Distance after stop and restart"
+    action: script
+    script: |
+      dev.stop_ranging()
+      d = dev.read()
+      result = isinstance(d, int)
+    expect_true: true
+    mode: [mock]
+
+  # ----- Hardware -----
+
   - name: "Distance in plausible range"
     action: call
     method: read